1. Field of the Invention
The present invention relates to a locking/unlocking mechanism for a center-matched double hinged door assembly for a vehicle body which has a closed position wherein a continuous aperture formed as a doorway at a side of the vehicle body is fully closed and an open position wherein the continuous aperture is fully opened.
2. Description of Related Art
Recent days some types of vehicles utilize double hinged door assemblies that open and close an aperture formed at the back of a vehicle body. One example of such a double hinged door assembly, that is installed to a van, is disclosed in Japanese Unexamined Patent Publication No. 8-142680. The double hinged door assembly installed as a back door to a van type of vehicle body comprises right and left hinged doors and a lock pillar having right and left strikers. The lock pillar is provided with a pillar lock device and right and left door lock devices. The pillar lock device comprises a lock pillar handle, mounted on a pivot shaft and upper and lower locks connected to the pivot shaft through upper and lower rods, respectively. These upper and lower locks are engaged with and disengaged from upper and lower strikers, respectively, according operated states of the lock pillar handle. The right door is provided with a right lock device that comprises a right outer handle and a right lock interconnected to the right outer handle so as to engage with and disengage from the right striker. Similarly, the left door is provided with a left lock device that comprises a left outer handle and a left lock interconnected to the left outer handle so as to engage with and disengage from the left striker. The right and left doors can be independently opened by releasing the right and left lock devices, respectively.
Though the double hinged door assembly installed to the van is structured to close a back aperture through which the vehicle is loaded and unloaded with goods, the right and left doors of the double hinged door assembly can be applied to front and rear doors for a side door that open and closes a side continuous aperture as a doorway of a passenger car. In the case where the double hinged door assembly is installed to a passenger car, the rear door can be opened prior to and independently from the front door. In consequence, when the rear door is opened while the front door remains closed, the rear door is possibly opened before the vehicle stops. This leads to a problem of passenger""s safety.
Another example of such a double hinged door assembly for side doors of a pick-up truck which has a continuous aperture extending from a front pillar to a rear pillar is disclosed in U.S. Pat. No. 4,930,836 to Gary J. Grinn. The double hinged door assembly comprises a front door mounted at the rear pillar, a front door pivotally mounted at the front pillar that moves to an overlying position with the rear door to effect closure of the reminder of the aperture, a primary latch assembly that is operatively disposed between the trailing edge of the front door and the leading edge of the rear door and a secondary latch assembly that is operatively disposed between portions of the vehicle body outside the continuous aperture. According to the double hinged door assembly, the rear door includes portions extending over the hinge mechanism through which pivotal mounting to the rear pillar is made to effect concealment of these hinges.
According to the double hinged door assembly, because the rear door is overlapped by the front door in their closed positions, the rear door is prevented from opening while the front door remains and, however, can not be closed when the front door is closed prior to the rear door.
It is an object of the present invention to provide a double hinged door assembly comprising front and rear hinged doors for a side door of a vehicle body having a continuous aperture as a doorway which provides reliable passenger""s safety.
It is another object of the present invention to provide a double hinged door assembly comprising front and rear hinged doors for a side door of a vehicle body having a continuous aperture as a doorway which provides an increased degree of freedom of opening and closing the rear door, that is, which prevents the rear door from opening while the front door remains closed, allows the rear door to open while the front door remains open, and allows the rear door to close regardless of whether the front door remains open or closed.
The aforesaid objects of the present invention are accomplished by a center-matched double hinged door assembly for a vehicle body having a continuous aperture as a doorway formed at each of opposite sides of the vehicle body which is movable between a closed position wherein the double hinged door assembly fully closes the continuous aperture and an open position wherein the double hinged door assembly fully opens the continuous aperture and comprises a front door hinged at a front end to the vehicle body which is movable between the closed position wherein the front door closes front part of the continuous aperture and the open position wherein the front door opens the front part of the continuous aperture and a rear door hinged at a rear end to the vehicle body which is movable between the closed position wherein the rear door closes rear part of the continuous aperture and the open position wherein the rear door opens the front part of the continuous aperture. The double hinged door assembly includes door lock/unlock means for preventing the rear door from moving to the open position while the front door is in the closed position, allowing the rear door to move to the open position while the front door is in the open position and allowing the rear door to move to the closed position irrespective of the closed and open positions of the front door.
The continuous side aperture may form the front part for a doorway to a driver""s seat or a front passenger""s seat, and rear part of the doorway for rear passengers"" seat.
According to the primary feature of the present invention, the lock/unlock control means prevents the rear door from opening while the front door remains closed, allowing the rear door to open while the front door remains open and further allowing the rear door to close irrespective of whether the front door remains closed or open. According to the center-matched double hinged door assembly that is structured so as to allow the front and rear doors to open in specified order, i.e. the rear door is allowed to open only after the front door opens, in consideration with passengers"" safety, the rear door is unconditionally allowed to close while the front door remains open. This provides the rear door with high serviceability.
The lock/unlock control means may include door position detection means such as a door position detection means and a door sensor that operates to detect the front door in the closed and open positions. The lock/unlock control means allows the rear door to move to the open position while the door position detection means detects the front door in the open position and prevents the rear door from moving to the open position while the door position detection means detects the front door in the closed position. The center-matched double hinged door assembly detects front door positions accurately and quickly and control opening and closing the rear door according to the result of detection.
According to another feature of the present invention, the door lock/unlock means comprises a rear door handle which is installed to the rear door and is operated to unlock the rear door, a door lock unit which is operative to lock the rear door to the vehicle body when the rear door moves to the closed position and to keep the rear door locked to the vehicle body until the rear door handle is operated, and an interlocking mechanism disposed in the rear door. The interlocking mechanism operationally couples the rear door handle to the door lock unit together to connect operation of the rear door handle to the door lock unit so as thereby to allow the door lock unit to unlock the rear door from the vehicle door upon the operation of the rear door handle while the door position detection means detects the front door in the open position and operationally uncouples the rear door handle from the door lock unit to disconnect the operation of the rear door handle so as thereby to prevent the door lock unit from unlocking the rear door from the vehicle door irrespective of the operation of the rear door handle while the door position detection means detects the front door in the closed position. The interlocking mechanism makes operation of the rear door handle ineffective while the front door is in the closed position, so that the rear door remains closed even when the rear door handle is operated. Since the interlocking mechanism has no necessity of a mechanism to coercively stop a release member or the like, the lock/unlock means itself can have improved durability.
The interlocking mechanism may be such as to mechanically connect operation of the rear door handle to the door lock unit so as to unlock the rear door from the vehicle body upon the operation of the rear door handle. The interlocking mechanism thus structured is mechanically locked to prevent the operation of the rear door handle so as thereby to prevent the door lock unit from unlocking the rear door from the vehicle body while the door position detection means detects the front door in the closed position and being unlocked to allow the operation of the rear door handle so as thereby to unlock the rear door from the vehicle body upon the operation of the rear door while the door position detection means detects the front door in the open position. Otherwise, the interlocking mechanism may be frictionally braked to prevent the operation of the rear door handle so as thereby to prevent the door lock unit from unlocking the rear door from the vehicle body while the door position detection means detects the front door in the closed position and being released to allow the operation of the rear door handle so as thereby to unlock the rear door from the vehicle body upon the operation of the rear door while the door position detection means detects the front door in the open position.
This interlocking mechanism can reliably prevent the operation of the rear door handle while the front door is in the closed position and can be simplified in structure.
According to still another feature of the present invention, the door lock/unlock means comprises a latch slider installed to a front end of the rear door and forced to retractably project from the rear door and a stopper fixedly disposed on a rear end of the front door and engageable with the latch slider so as thereby to prevent the rear door from moving to the closed position while the front and rear doors are in the closed position. The latch slider has a front end facing the front door so shaped that, while the front door is in the closed position, the latch slider is forced back into the rear door by the stopper when the rear door moves toward the closed position and is brought into engagement with the stopper when the rear door reaches the closed position. The stopper may be formed as an integral part of the front door or a separate part from the front door.
With the lock/unlock control means, the stopper stops the latch slider forced out from the rear door when the rear door is pushed in an attempt to open the rear door while the front door remains in the closed position, the rear door is prevented from opening. On the other hand, the stopper forces back the latch slider into the rear door when the rear door is moved toward the closed position after the front door is closed, so that the rear door is completely closed. Since this lock/unlock control means basically comprises the stopper and the latch slider only, the lock/unlock control means can be simplified in structure and has no necessity of using electrical control and electric power.